This thesis aims to investigate if the endothelial protein C receptor is expressed in the murine kidney. This was done by performing flow cytometry and Western blot analysis on cultivated murine kidney endothelial cells (mKECs) as well as SDS-PAGE and Western blot analysis on murine kidney tissue. Flow cytometry was also performed on cultivated ARPE19 and 4T1 cells for comparison. It was discovered that ≥95,5% of the mKECs, ≥93,6% of the ARPE19 cells and ≥60,9% of the 4T1 cells express the receptor according to the flow cytometry data. A dot blot was performed to validate the primary antibody used for detection of EPCR in Western blot and SDS-PAGE. According to the dot blot, the primary antibody can be visualised in the dilution range from 1:2000 to 1:10. The dot blot also showed that the secondary antibody binds specifically to the primary antibody. Yet, Western blot analysis did not detect the receptor neither in mKECs nor tissue lysate. This was likely due to the fact that the primary antibody used did not bind specifically to the receptor, and may not be applicable for this method. SDS-PAGE did not show any indication that the receptor was present in the kidney tissue. In conclusion, it was discovered that the EPCR was expressed in the murine kidneys endothelial cells through flow cytometry, but the presented methods for Western blot and SDS-PAGE could not confirm the expression of the receptor.

No description available.

No description available.

L'objectif principal de ce travail était de comparer l'implication (i) de cellules vasculaires, cellules musculaires lisses vasculaires (CML) et cellules endothéliales (CE), ou des cellules circulantes, les plaquettes, et (ii) des microparticules (MP) issues de ces différentes cellules dans la génération de la thrombine mais également dans son inhibition par les systèmes anticoagulants de la protéine C activée (PCa) et de l'inhibiteur de la voie du facteur tissulaire (TFPI), et d'identifier les mécanismes et les déterminants responsables des différences observées entre ces supports cellulaires pour la coagulation. Nous avons démontré que l'intégrine [alpha]v[gamma]3 qui est le récepteur pour la prothrombine sur les surfaces vasculaires était impliquée dans la génération de thrombine à la surface des CML soumises ou non à des déformations mécaniques cycliques. A l'état de base, les CML et les CE ont un potentiel thrombinique similaire, mais moins important que celui des plaquettes. Nous avons montré un rôle synergique du TFPI avec la PCa dans l'inhibition de la génération de thrombine à la surface de ces cellules plus importante avec les CML qu'avec les CE. L'ensemble de nos résultats suggère que les CML pourraient exercer des effets procoagulants comparables aux CE mais avec des régulations différentes en réponse aux facteurs pro- et anticoagulants, et que les MP issues de cellules vasculaires ont un pouvoir thrombogène très supérieur à leurs cellules d'origine / The main objective of this study was to compare the implication (i) of vascular cells, smooth muscle cells (SMC) and endothelial cells (EC), or circulating cells, platelets, and (ii) microparticles (MP) derived from these different cells in the generation of thrombin but also in its inhibition by the activated protein C (APC) and the tissue factor pathway inhibitor (TFPI), and to identify the mechanisms and determinants responsibles for observed differences between these different cell supports for coagulation. We have demonstrated that [alpha]v[gamma]3 integrin, the prothrombin receptor on the vascular surfaces, was involved in the generation of thrombin on the surface of these cells subjected or not subjected to cyclic mechanical deformations. At baseline, SMC and EC, have equivalent thrombin generating capacities, but less than that of platelets. We have shown a synergistic role of TFPI with APC in the inhibition of thrombin generation at the surface of these cells, more important with SMC than with EC. Taken together, our results suggest that SMC may exert procoagulant effects comparable to EC but with different regulations in response to pro-and anticoagulant factors, and that MP derived from vascular cells have a very higher thrombogenic activity compared to their parent cells

L'ischémie/reperfusion (I/R) est un phénomène très fréquent en clinique humaine. Ce phénomène est observé lors de la désobstruction d'une artère digestive, du traitement d'un état de choc, ainsi qu'au cours d'autres pathologies. L'interruption de la perfusion tissulaire (ischémie) et le rétablissement de celle-ci (reperfusion) sont la cause de la mise en place de troubles hémodynamiques et métaboliques. L'I/R est souvent présentée comme étant la principale source de l'hyperlactatémie et le moteur de la réponse inflammatoire lors des états de choc (cardiogénique, hypovolémique, septique). Parallèlement, elle est responsable de l'induction de la production de la libération des espèces réactives de l'oxygène, des cytokines et du monoxyde d'azote. Suite à un choc hémorragique par Ischémie/reperfusion chez le rat, nous avons montré que 1) le NaHS, donneur d'H2S limite la diminution de la pression artérielle moyenne et diminue le lactate plasmatique, témoin de la souffrance tissulaire, 2) cette amélioration hémodynamique est associée à une baisse de l'expression myocardique des ARNm d'iNOS, une diminution de la concentration des dérivés NOx plasmatiques et une diminution des concentrations aortiques et myocardiques de NO et d'anion superoxyde et 3) l'inhibition d'H2S par la DL-propargylglycine aggrave le tableau hémodynamique et les conséquences tissulaires du choc. Dans un autre modèle d'ischémie/reperfusion intestinale, les résultats obtenus, montrent que l'administration de la Protéine C activée (PCa) ou de la dexaméthaosne (Dexa) : 1) améliore la PAM et la réactivité vasculaire, 2) permet d'augmenter le pH et de diminuer la lactatémie, 3) diminue la production des cytokines pro-inflammatoires et 4) inhibe les médiateurs de l'apoptose. Ces résultats sont reliés à une down régulation d'iNOS, une restauration de la voie Akt/eNOS et à une resensibilisation des adrénorécepteurs alpha. Ces résultats ouvrent de nouvelles perspectives cliniques dans les traitements de l'I/R / Ischemia/reperfusion (I/R) is a very common phenomenon, observed during intestinal artery surgery, shock treatment, as well as in several other diseases. The disruption of tissue perfusion (ischemia) and recovery (reperfusion) induce hemodynamic and metabolic dysfunction. Gut ischemia/reperfusion is often presented as the main source of lactate and the motor of the inflammatory response, such as cardiogenic, hypovolemic and septic shock. In parallel, gut reperfusion produces numerous mediators such as reactive oxygen metabolites, pro-inflammatory cytokines, and high concentrations of nitric oxide. In a model of ischemia/reperfusion induced by hemorrhagic shock, we found that 1) NaHS an injectable form of H2S, limited the decrease in arterial pressure induced by shock and decreased plasmatic lactate, a witness of tissue suffering, 2) this hemodynamic improvement was associated with a fall in myocardial iNOS mRNA expression, a reduction in the concentration of plasmatic NOx and a reduction of aortic and myocardial concentrations of NO and superoxide anion and 3) the inhibition of H2S with DL-propargylglycine worsened hemodynamics and tissue consequences of shock An experimental model of intestinal I/R has been developed, we demonstrated that the administration of APC or Dexa : 1) Improves MAP and vascular reactivity, 2) increased pH and decreased lactate, 3) decreased pro-inflammatory cytokines production and 4) inhibited apoptosis mediators expression. These results are related to a down regulation of iNOS, to a restoration of the AKT/eNOS pathway, and to alpha-adrenoreceptor resensitization. These results open new perspectives in clinical treatment of I/R

Objetivo: A trombose da veia porta é uma causa importante de hiper-tensão porta em crianças e adolescentes, porém, em uma proporção importante dos casos, não apresenta fator etiológico definido. O objetivo desse estudo é determinar a freqüência de deficiência das proteínas inibidoras da coagulação – proteínas C, S e antitrombina − e das mutações fator V Leiden, G20210A no gene da protrombina e C677T da metileno-tetraidrofolato redutase em crianças e adolescentes com trom-bose da veia porta, definir o padrão hereditário de uma eventual deficiência das pro-teínas inibidoras da coagulação nesses pacientes e avaliar a freqüência da deficiên-cia dessas proteínas em crianças e adolescentes com cirrose. Casuística e Métodos: Foi realizado um estudo prospectivo com 14 crianças e adolescentes com trombose da veia porta, seus pais (n = 25) e dois gru-pos controles pareados por idade, constituídos por um grupo controle sem hepato-patia (n = 28) e um com cirrose (n = 24). A trombose da veia porta foi diagnosticada por ultra-sonografia abdominal com Doppler e/ou fase venosa do angiograma celíaco seletivo. A dosagem da atividade das proteínas C, S e antitrombina foi determinada em todos os indivíduos e a pesquisa das mutações fator V Leiden, G20210A da pro-trombina e C677T da metileno-tetraidrofolato redutase, nas crianças e adolescentes com trombose da veia porta, nos pais, quando identificada a mutação na criança, e nos controles sem hepatopatia. Resultados: Foram avaliados 14 pacientes caucasóides, com uma média e desvio padrão de idade de 8 anos e 8 meses ± 4 anos e 5 meses e do diagnóstico de 3 anos e 8 meses ± 3 anos e seis meses. Metade dos pacientes pertenciam ao gênero masculino. O motivo da investigação da trombose da veia porta foi hemorra-gia digestiva alta em 9/14 (64,3%) e achado de esplenomegalia ao exame físico em 5/14 (35,7%). Anomalias congênitas extra-hepáticas foram identificadas em 3/14 (21,4%) e fatores de risco adquiridos em 5/14 (35,7%) dos pacientes. Nenhum pa-ciente tinha história familiar de consangüinidade ou trombose venosa. A deficiência das proteínas C, S e antitrombina foi constatada em 6/14 (42,9%) (p < 0,05 vs con-troles sem hepatopatia), 3/14 (21,4%) (p > 0,05) e 1/14 (7,1%) (p > 0,05) pacientes com trombose da veia porta, respectivamente. A deficiência dessas proteínas não foi identificada em nenhum dos pais ou controles sem hepatopatia. A mutação G20210A no gene da protrombina foi identificada em um paciente com trombose da veia porta e em um controle sem hepatopatia (p = 0,999), mas em nenhum desses foi identificado a mutação fator V Leiden. A mutação C677T da metileno-tetraidrofo-lato redutase foi observada na forma homozigota, em 3/14 (21,4%) dos pacientes com trombose da veia porta e em 5/28 (17,9%) controles sem hepatopatia (p = 0,356). A freqüência da deficiência das proteínas C, S e antitrombina nos pacientes com cir-rose foi de 14/24 (58,3%), 7/24 (29,2%) e 11/24 (45,8%), respectivamente (p < 0,05 vs controles sem hepatopatia), sendo mais freqüente nos pacientes do subgrupo Child-Pugh B ou C, que foi de 11/12 (91,7%), 5/12 (41,7%) e 9/12 (75%), respectivamente (p < 0,05 vs controles sem hepatopatia). Conclusões: A deficiência de proteína C foi freqüente nas crianças e adolescentes com trombose da veia porta e não parece ser de origem genética. A deficiência de proteína S, antitrombina e as presenças das mutações G20210A da protrombina e C677T da metileno-tetraidrofolato redutase foram observadas mas não apresentaram diferença estatística significativa em relação ao grupo controle sem hepatopatia. O fator V Leiden não foi identificado. Os resultados deste estudo sugerem que a deficiência da proteína C pode ocorre como conseqüência da hiper-tensão porta. Os distúrbios pró-trombóticos hereditários não parecem apresentar um papel importante em relação à trombose nas crianças e adolescentes estudadas. / Objective: Portal vein thrombosis is a major cause of portal hypertension in children and adolescents; yet, its etiology is not clearly defined in a considerable number of cases. The present study aims at determining the prevalence of blood coagulation disorders – protein C, protein S and antithrombin – and factor V Leiden, G20210A prothrombin, and C677T methylenetetrahydrofolate reductase mutations in children and adolescents with portal vein thrombosis, as well as assessing the hereditary character of these disorders in these patients, and also evaluating the prevalence of blood coagulation disorders in children and adolescents with cirrhosis. Study design: A prospective study was carried out, including children and adolescents with portal vein thrombosis (n = 14), their parents (n = 25), two age-matched control groups, one without liver disease (n = 28), and another with cirrhosis (n = 24). Portal vein thrombosis was diagnosed through abdominal Doppler ultrasonography and/or venous phase of selective coeliac angiograms. The activity of protein C, protein S and antithrombin was evaluated for all individuals; the presence of factor V Leiden, G20210A prothrombin, and C677T methylenetetrahydrofolate reductase gene mutations was investigated in children and adolescents with portal vein thrombosis, in parents when their respective children presented any of these mutations, and in the control group without liver disease. Results: 14 Caucasian patients were assessed. The mean and standard deviation for age were 8 years and 8 months ± 4 years and 5 months while the mean and standard deviation for diagnosis were 3 years and 8 months ± 3 years and six months. Half of the patients were males. Initial clinical manifestations upon diagnosis were digestive hemorrhage in 9/14 (64.3%) and splenomegaly on physical examination in 5/14 individuals (35.7%). Patients presented extrahepatic anomalies in 3/14 (21.4%) and acquired risk factors in 5/14 (35.7%) of the cases. None of the patients had a family history of consanguinity or venous thrombosis. The frequency of protein C, protein S and antithrombin deficiency was observed in 6/14 (42.9%) (p < 0.05 vs. controls without liver disease), 3/14 (21.4%) (p > 0.05) and 1/14 (7.1%) (p > 0.05) of patients, respectively. None of the portal vein thombosis patients or controls presented protein C, S or antithrombin deficiency. One portal vein patient and one control (p = 0.999) presented G20210A prothrombin mutation. None of these patients presented the factor V Leiden. The homozygous form of C677T methylenetetrahydrofolate reductase mutation was observed in 3/14 patients with portal vein thrombosis (21.4%) and in 5/28 controls (17.9%) (p = 0.356). The frequency of coagulation inhibitor deficiency was high in cirrhotic patients (14/24 (58.3%) PC, 7/24 (29.2%) PS and 11/24 (45.8%) AT; p < 0.05 vs. controls), especially in Child-Pugh B and C patients (11/12 (91.7%) PC, 5/12 (41.7%) PS and 9/12 (75%) AT; p < 0.05 vs. controls). Conclusions: Protein C deficiency was frequent in children and adolescents with portal vein thrombosis and does not seem to be an inherited condition. Protein S and antithrombin deficiency, and G20210A prothrombin and C677T methylenetetrahydrofolate reductase mutations were observed but did not present statistically significant differences when compared to the controls without liver disease. Factor V Leiden was not observed. The results suggest the protein C deficiency may originates from portal hypertension. The hereditary prothrombotic disorders do not seem to play a vital role in thrombosis in children and adolescents with portal vein thrombosis.

Objetivo: A trombose da veia porta é uma causa importante de hiper-tensão porta em crianças e adolescentes, porém, em uma proporção importante dos casos, não apresenta fator etiológico definido. O objetivo desse estudo é determinar a freqüência de deficiência das proteínas inibidoras da coagulação – proteínas C, S e antitrombina − e das mutações fator V Leiden, G20210A no gene da protrombina e C677T da metileno-tetraidrofolato redutase em crianças e adolescentes com trom-bose da veia porta, definir o padrão hereditário de uma eventual deficiência das pro-teínas inibidoras da coagulação nesses pacientes e avaliar a freqüência da deficiên-cia dessas proteínas em crianças e adolescentes com cirrose. Casuística e Métodos: Foi realizado um estudo prospectivo com 14 crianças e adolescentes com trombose da veia porta, seus pais (n = 25) e dois gru-pos controles pareados por idade, constituídos por um grupo controle sem hepato-patia (n = 28) e um com cirrose (n = 24). A trombose da veia porta foi diagnosticada por ultra-sonografia abdominal com Doppler e/ou fase venosa do angiograma celíaco seletivo. A dosagem da atividade das proteínas C, S e antitrombina foi determinada em todos os indivíduos e a pesquisa das mutações fator V Leiden, G20210A da pro-trombina e C677T da metileno-tetraidrofolato redutase, nas crianças e adolescentes com trombose da veia porta, nos pais, quando identificada a mutação na criança, e nos controles sem hepatopatia. Resultados: Foram avaliados 14 pacientes caucasóides, com uma média e desvio padrão de idade de 8 anos e 8 meses ± 4 anos e 5 meses e do diagnóstico de 3 anos e 8 meses ± 3 anos e seis meses. Metade dos pacientes pertenciam ao gênero masculino. O motivo da investigação da trombose da veia porta foi hemorra-gia digestiva alta em 9/14 (64,3%) e achado de esplenomegalia ao exame físico em 5/14 (35,7%). Anomalias congênitas extra-hepáticas foram identificadas em 3/14 (21,4%) e fatores de risco adquiridos em 5/14 (35,7%) dos pacientes. Nenhum pa-ciente tinha história familiar de consangüinidade ou trombose venosa. A deficiência das proteínas C, S e antitrombina foi constatada em 6/14 (42,9%) (p < 0,05 vs con-troles sem hepatopatia), 3/14 (21,4%) (p > 0,05) e 1/14 (7,1%) (p > 0,05) pacientes com trombose da veia porta, respectivamente. A deficiência dessas proteínas não foi identificada em nenhum dos pais ou controles sem hepatopatia. A mutação G20210A no gene da protrombina foi identificada em um paciente com trombose da veia porta e em um controle sem hepatopatia (p = 0,999), mas em nenhum desses foi identificado a mutação fator V Leiden. A mutação C677T da metileno-tetraidrofo-lato redutase foi observada na forma homozigota, em 3/14 (21,4%) dos pacientes com trombose da veia porta e em 5/28 (17,9%) controles sem hepatopatia (p = 0,356). A freqüência da deficiência das proteínas C, S e antitrombina nos pacientes com cir-rose foi de 14/24 (58,3%), 7/24 (29,2%) e 11/24 (45,8%), respectivamente (p < 0,05 vs controles sem hepatopatia), sendo mais freqüente nos pacientes do subgrupo Child-Pugh B ou C, que foi de 11/12 (91,7%), 5/12 (41,7%) e 9/12 (75%), respectivamente (p < 0,05 vs controles sem hepatopatia). Conclusões: A deficiência de proteína C foi freqüente nas crianças e adolescentes com trombose da veia porta e não parece ser de origem genética. A deficiência de proteína S, antitrombina e as presenças das mutações G20210A da protrombina e C677T da metileno-tetraidrofolato redutase foram observadas mas não apresentaram diferença estatística significativa em relação ao grupo controle sem hepatopatia. O fator V Leiden não foi identificado. Os resultados deste estudo sugerem que a deficiência da proteína C pode ocorre como conseqüência da hiper-tensão porta. Os distúrbios pró-trombóticos hereditários não parecem apresentar um papel importante em relação à trombose nas crianças e adolescentes estudadas. / Objective: Portal vein thrombosis is a major cause of portal hypertension in children and adolescents; yet, its etiology is not clearly defined in a considerable number of cases. The present study aims at determining the prevalence of blood coagulation disorders – protein C, protein S and antithrombin – and factor V Leiden, G20210A prothrombin, and C677T methylenetetrahydrofolate reductase mutations in children and adolescents with portal vein thrombosis, as well as assessing the hereditary character of these disorders in these patients, and also evaluating the prevalence of blood coagulation disorders in children and adolescents with cirrhosis. Study design: A prospective study was carried out, including children and adolescents with portal vein thrombosis (n = 14), their parents (n = 25), two age-matched control groups, one without liver disease (n = 28), and another with cirrhosis (n = 24). Portal vein thrombosis was diagnosed through abdominal Doppler ultrasonography and/or venous phase of selective coeliac angiograms. The activity of protein C, protein S and antithrombin was evaluated for all individuals; the presence of factor V Leiden, G20210A prothrombin, and C677T methylenetetrahydrofolate reductase gene mutations was investigated in children and adolescents with portal vein thrombosis, in parents when their respective children presented any of these mutations, and in the control group without liver disease. Results: 14 Caucasian patients were assessed. The mean and standard deviation for age were 8 years and 8 months ± 4 years and 5 months while the mean and standard deviation for diagnosis were 3 years and 8 months ± 3 years and six months. Half of the patients were males. Initial clinical manifestations upon diagnosis were digestive hemorrhage in 9/14 (64.3%) and splenomegaly on physical examination in 5/14 individuals (35.7%). Patients presented extrahepatic anomalies in 3/14 (21.4%) and acquired risk factors in 5/14 (35.7%) of the cases. None of the patients had a family history of consanguinity or venous thrombosis. The frequency of protein C, protein S and antithrombin deficiency was observed in 6/14 (42.9%) (p < 0.05 vs. controls without liver disease), 3/14 (21.4%) (p > 0.05) and 1/14 (7.1%) (p > 0.05) of patients, respectively. None of the portal vein thombosis patients or controls presented protein C, S or antithrombin deficiency. One portal vein patient and one control (p = 0.999) presented G20210A prothrombin mutation. None of these patients presented the factor V Leiden. The homozygous form of C677T methylenetetrahydrofolate reductase mutation was observed in 3/14 patients with portal vein thrombosis (21.4%) and in 5/28 controls (17.9%) (p = 0.356). The frequency of coagulation inhibitor deficiency was high in cirrhotic patients (14/24 (58.3%) PC, 7/24 (29.2%) PS and 11/24 (45.8%) AT; p < 0.05 vs. controls), especially in Child-Pugh B and C patients (11/12 (91.7%) PC, 5/12 (41.7%) PS and 9/12 (75%) AT; p < 0.05 vs. controls). Conclusions: Protein C deficiency was frequent in children and adolescents with portal vein thrombosis and does not seem to be an inherited condition. Protein S and antithrombin deficiency, and G20210A prothrombin and C677T methylenetetrahydrofolate reductase mutations were observed but did not present statistically significant differences when compared to the controls without liver disease. Factor V Leiden was not observed. The results suggest the protein C deficiency may originates from portal hypertension. The hereditary prothrombotic disorders do not seem to play a vital role in thrombosis in children and adolescents with portal vein thrombosis.

Objetivo: A trombose da veia porta é uma causa importante de hiper-tensão porta em crianças e adolescentes, porém, em uma proporção importante dos casos, não apresenta fator etiológico definido. O objetivo desse estudo é determinar a freqüência de deficiência das proteínas inibidoras da coagulação – proteínas C, S e antitrombina − e das mutações fator V Leiden, G20210A no gene da protrombina e C677T da metileno-tetraidrofolato redutase em crianças e adolescentes com trom-bose da veia porta, definir o padrão hereditário de uma eventual deficiência das pro-teínas inibidoras da coagulação nesses pacientes e avaliar a freqüência da deficiên-cia dessas proteínas em crianças e adolescentes com cirrose. Casuística e Métodos: Foi realizado um estudo prospectivo com 14 crianças e adolescentes com trombose da veia porta, seus pais (n = 25) e dois gru-pos controles pareados por idade, constituídos por um grupo controle sem hepato-patia (n = 28) e um com cirrose (n = 24). A trombose da veia porta foi diagnosticada por ultra-sonografia abdominal com Doppler e/ou fase venosa do angiograma celíaco seletivo. A dosagem da atividade das proteínas C, S e antitrombina foi determinada em todos os indivíduos e a pesquisa das mutações fator V Leiden, G20210A da pro-trombina e C677T da metileno-tetraidrofolato redutase, nas crianças e adolescentes com trombose da veia porta, nos pais, quando identificada a mutação na criança, e nos controles sem hepatopatia. Resultados: Foram avaliados 14 pacientes caucasóides, com uma média e desvio padrão de idade de 8 anos e 8 meses ± 4 anos e 5 meses e do diagnóstico de 3 anos e 8 meses ± 3 anos e seis meses. Metade dos pacientes pertenciam ao gênero masculino. O motivo da investigação da trombose da veia porta foi hemorra-gia digestiva alta em 9/14 (64,3%) e achado de esplenomegalia ao exame físico em 5/14 (35,7%). Anomalias congênitas extra-hepáticas foram identificadas em 3/14 (21,4%) e fatores de risco adquiridos em 5/14 (35,7%) dos pacientes. Nenhum pa-ciente tinha história familiar de consangüinidade ou trombose venosa. A deficiência das proteínas C, S e antitrombina foi constatada em 6/14 (42,9%) (p < 0,05 vs con-troles sem hepatopatia), 3/14 (21,4%) (p > 0,05) e 1/14 (7,1%) (p > 0,05) pacientes com trombose da veia porta, respectivamente. A deficiência dessas proteínas não foi identificada em nenhum dos pais ou controles sem hepatopatia. A mutação G20210A no gene da protrombina foi identificada em um paciente com trombose da veia porta e em um controle sem hepatopatia (p = 0,999), mas em nenhum desses foi identificado a mutação fator V Leiden. A mutação C677T da metileno-tetraidrofo-lato redutase foi observada na forma homozigota, em 3/14 (21,4%) dos pacientes com trombose da veia porta e em 5/28 (17,9%) controles sem hepatopatia (p = 0,356). A freqüência da deficiência das proteínas C, S e antitrombina nos pacientes com cir-rose foi de 14/24 (58,3%), 7/24 (29,2%) e 11/24 (45,8%), respectivamente (p < 0,05 vs controles sem hepatopatia), sendo mais freqüente nos pacientes do subgrupo Child-Pugh B ou C, que foi de 11/12 (91,7%), 5/12 (41,7%) e 9/12 (75%), respectivamente (p < 0,05 vs controles sem hepatopatia). Conclusões: A deficiência de proteína C foi freqüente nas crianças e adolescentes com trombose da veia porta e não parece ser de origem genética. A deficiência de proteína S, antitrombina e as presenças das mutações G20210A da protrombina e C677T da metileno-tetraidrofolato redutase foram observadas mas não apresentaram diferença estatística significativa em relação ao grupo controle sem hepatopatia. O fator V Leiden não foi identificado. Os resultados deste estudo sugerem que a deficiência da proteína C pode ocorre como conseqüência da hiper-tensão porta. Os distúrbios pró-trombóticos hereditários não parecem apresentar um papel importante em relação à trombose nas crianças e adolescentes estudadas. / Objective: Portal vein thrombosis is a major cause of portal hypertension in children and adolescents; yet, its etiology is not clearly defined in a considerable number of cases. The present study aims at determining the prevalence of blood coagulation disorders – protein C, protein S and antithrombin – and factor V Leiden, G20210A prothrombin, and C677T methylenetetrahydrofolate reductase mutations in children and adolescents with portal vein thrombosis, as well as assessing the hereditary character of these disorders in these patients, and also evaluating the prevalence of blood coagulation disorders in children and adolescents with cirrhosis. Study design: A prospective study was carried out, including children and adolescents with portal vein thrombosis (n = 14), their parents (n = 25), two age-matched control groups, one without liver disease (n = 28), and another with cirrhosis (n = 24). Portal vein thrombosis was diagnosed through abdominal Doppler ultrasonography and/or venous phase of selective coeliac angiograms. The activity of protein C, protein S and antithrombin was evaluated for all individuals; the presence of factor V Leiden, G20210A prothrombin, and C677T methylenetetrahydrofolate reductase gene mutations was investigated in children and adolescents with portal vein thrombosis, in parents when their respective children presented any of these mutations, and in the control group without liver disease. Results: 14 Caucasian patients were assessed. The mean and standard deviation for age were 8 years and 8 months ± 4 years and 5 months while the mean and standard deviation for diagnosis were 3 years and 8 months ± 3 years and six months. Half of the patients were males. Initial clinical manifestations upon diagnosis were digestive hemorrhage in 9/14 (64.3%) and splenomegaly on physical examination in 5/14 individuals (35.7%). Patients presented extrahepatic anomalies in 3/14 (21.4%) and acquired risk factors in 5/14 (35.7%) of the cases. None of the patients had a family history of consanguinity or venous thrombosis. The frequency of protein C, protein S and antithrombin deficiency was observed in 6/14 (42.9%) (p < 0.05 vs. controls without liver disease), 3/14 (21.4%) (p > 0.05) and 1/14 (7.1%) (p > 0.05) of patients, respectively. None of the portal vein thombosis patients or controls presented protein C, S or antithrombin deficiency. One portal vein patient and one control (p = 0.999) presented G20210A prothrombin mutation. None of these patients presented the factor V Leiden. The homozygous form of C677T methylenetetrahydrofolate reductase mutation was observed in 3/14 patients with portal vein thrombosis (21.4%) and in 5/28 controls (17.9%) (p = 0.356). The frequency of coagulation inhibitor deficiency was high in cirrhotic patients (14/24 (58.3%) PC, 7/24 (29.2%) PS and 11/24 (45.8%) AT; p < 0.05 vs. controls), especially in Child-Pugh B and C patients (11/12 (91.7%) PC, 5/12 (41.7%) PS and 9/12 (75%) AT; p < 0.05 vs. controls). Conclusions: Protein C deficiency was frequent in children and adolescents with portal vein thrombosis and does not seem to be an inherited condition. Protein S and antithrombin deficiency, and G20210A prothrombin and C677T methylenetetrahydrofolate reductase mutations were observed but did not present statistically significant differences when compared to the controls without liver disease. Factor V Leiden was not observed. The results suggest the protein C deficiency may originates from portal hypertension. The hereditary prothrombotic disorders do not seem to play a vital role in thrombosis in children and adolescents with portal vein thrombosis.

Introduction: Au moins 30% des AVC ischémiques chez les jeunes demeurent inexpliqués malgré une investigation extensive. Le rôle de certains états prothrombotiques (ÉP) dans la thrombose artérielle reste incertain, possiblement à cause du petit nombre de patients, de populations hétérogènes ou d’ÉP analysés individuellement dans les études antérieures, alors que leur prévalence est basse. Méthodologie : Étude cas-témoins sur une cohorte rétrospective (2002-2011). Les patients âgés de ≤50ans lors d’un AVC ischémique furent identifiés sur une base de données hospitalière. Après exclusion des individus ayant une investigation étiologique incomplète, un syndrome antiphospholipide ou aucun ÉP testé, la cohorte fut divisée en groupes cas (AVC idiopathique) et témoins (étiologie identifiée). La prevalence de chaque ÉP fut comparée entre les groupe, ainsi que la présence de ≥2 ÉP (analyse primaire), sans et avec ajustement pour les facteurs de risque non-prothrombotiques (régression logistique). En analyse de sous-groupe, la présence de ≥1 ÉP fut comparée entre les cas avec versus sans foramen ovale perméable (FOP), entre les cas ou contrôles porteurs d’un FOP avec versus sans migraine, de même qu’entre les cas versus témoins de sexe féminin en incluant la contraception orale parmi les ÉP. Résultats : 502 jeunes avec AVC ischémique furent identifiés. Après exclusion de 108 patients, 184 cas et 210 témoins furent comparés, (âge moyen : 39,2 ans, 51% hommes). La prévalence des ÉP ne différait pas entre les cas et contrôles : déficits en protéine S (0,6%), protéine C (3,4%), antithrombine (1,2%), mutation de la prothrombine (2,5%), facteur V Leiden (4,6%), et anticardiolipines (titre 15-40 unités GPL ou MPL; 3,3%). La présence de ≥2 ÉP n’était pas associée à l’AVC idiopathique, avant (p=0,48) ou après ajustement (p=0,74). La présence de ≥1 ÉP ne différait pas entre les sous-groupes étudiés. Conclusion: Il n’y a pas d’association entre les ÉP, isolés ou en association, avec l’AVC ischémique idiopathique chez les jeunes, même en presence de FOP ou de migraine. / Background: Despite extensive workup, more than 30% of ischemic strokes in young adults remain idiopathic. The role of some prothrombotic factors (PF) in arterial thrombosis remains unclear in previous studies. This may be due to small sample sizes, heterogeneous characteristics of populations studied, or analyzing individual PF with low prevalence. Methods: We conducted a case-control study using a retrospective cohort (2002-2011). From a hospital database, we identified patients with ischemic stroke at age ≤50 years. We excluded patients with incomplete baseline investigation or antiphospholipid syndrome, and those without prothrombotic testing. We compared the prevalence of each PF, as well as the presence of ≥2 PF (primary analysis) between cases with idiopathic stroke and controls with defined stroke etiology, before and after adjusting for non-prothrombotic risk factors. By subgroup analysis, we compared the presence of ≥1 PF between cases with versus without patent foramen ovale (PFO), between cases or controls with PFO with versus without migraine, as well as between women (cases versus controls), including oral contraceptives among PF. Results: 502 young ischemic stroke patients were identified. We excluded 108 patients. We analyzed 184 cases and 210 controls (Mean age : 39.2 y-o, 51% male). Prevalence of individual PF did not differ between cases and controls : protein S (0.6%), protein C (3.4%), antithrombin (1.2%) deficiencies, mutant prothrombin (2.5%), factor V Leiden (4.6%), and total anticardiolipin (titers 15-40 units GPL or MPL; 3,3%). There was no association between the presence of ≥2 PF and idiopathic stroke, before (p=0,48) and after adjusting for non-prothrombotic risk factors (p= 0,74). No differences were observed between subgroups for the presence of ≥1 PF. Conclusion: There is no association between prothrombotic risk factors (analyzed individually or as a group) and idiopathic ischemic stroke in the young, even in those with a PFO or with migraine.

O objetivo do presente estudo foi avaliar a diferença de resultados maternos e neonatais em gestações complicadas por trombofilias hereditárias em pacientes com e sem tromboembolismo venoso. Apesar do aumento de evidências, na literatura, sobre a associação de trombofilias congênitas e resultados obstétricos adversos, há ainda dúvida se pacientes trombofílicas com tromboembolismo venoso apresentam resultados maternos e neonatais piores que as pacientes trombofílicas sem tromboembolismo venoso. O estudo analisou 66 gestantes com trombofilias hereditárias, de forma retrospectiva observacional e comparativa, das quais 33 apresentavam tromboembolismo venoso e 36 o não apresentavam. Os principais desfechos relacionados a resultados maternos e neonatais adversos foram: pré-eclâmpsia grave, descolamento prematuro de placenta, restrição de crescimento fetal, natimortalidade, prematuridade e complicações hemorrágicas maternas. As trombofilias congênitas incluídas no estudo foram o fator V de Leiden (FVL), mutação da protrombina G20210A, mutação C677T do gene da 5,10-metilenotetrahidrofolato redutase (MTHFR), deficiência de proteína S, deficiência de proteína C e deficiência de antitrombina. Ambos os grupos apresentaram características populacionais similares. A ocorrência de complicações maternas e fetais/neonatais foi similar nos dois grupos: pré-eclâmpsia grave (P=0,097), descolamento prematuro de placenta (P=0,478), restrição de crescimento fetal (P=0,868), natimortalidade (P=0,359), prematuridade (P=0,441) e complicações hemorrágicas maternas (P=0,478). Este estudo concluiu que a presença de tromboembolismo venoso em gestantes com trombofilia hereditária apresenta resultados maternos e neonatais semelhantes àquelas com trombofilias hereditárias sem tromboembolismo venoso. / The aim of this study was to evaluate differences in maternal and neonatal outcomes in pregnancies complicated by inherited thrombophilias between patients with and without venous thromboembolism. Despite increasing evidence in the literature indicating an association between inherited thrombophilias and adverse obstetric outcomes, doubts remain whether thrombophilic patients with venous thromboembolism present poorer maternal and neonatal outcomes than thrombophilic patients without venous thromboembolism. In this retrospective, observational and comparative study, 66 pregnant women with inherited thrombophilias, including 33 with venous thromboembolism and 36 without thromboembolism, were investigated. The main end-points analyzed were severe pre-eclampsia, placental abruption, fetal growth restriction, stillbirth, preterm delivery, and maternal hemorrhagic complications. The congenital thrombophilias included in this study were factor V Leiden (FVL), prothrombin G20210A mutation, C677T mutation in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, protein S deficiency, protein C deficiency, and antithrombin deficiency. The two groups were similar in terms of population characteristics. The frequency of maternal and fetal/neonatal complications was similar in the two groups: severe pre-eclampsia (P=0.097), placental abruption (P=0.478), fetal growth restriction (P=0.868), stillbirth (P=0.359), preterm delivery (P=0.441), and maternal hemorrhagic complications (P=0.478). This study concluded that venous thromboembolism in thrombophilic patients does not worsen maternal or neonatal outcomes when compared to thrombophilic patients without venous thromboembolism.